code: def _predict(self, params):
      x = self.exog
      a, b, c = params
      return a * np.exp(-b * x) + c
  
file_path: statsmodels/statsmodels/miscmodels/nonlinls.py
imports: import numpy
  from scipy import optimize
  from statsmodels.base.model import Model
label_desc: Use image node_id 1 for calling the Myfunc obj's underlying member method code with example usage: obj._predict(params) and returns: unknown